A TIG (Tungsten Inert Gas) welding torch is mounted in a seam tracker and manipulated by a robot arm to melt filler wire, fusing separate workpieces or panels of an automotive body together at a weld seam. The welding torch includes a tungsten electrode that should be easily aligned in a direction transverse to the weld seam with the filler wire. When the electrode is removed from the welding torch, it is important that the positioning of the new electrode is repeatable to eliminate time consuming recalibration of the welding torch.
In prior welding torches, a long electrode is employed having a length of about 4.25 inch. When the electrode needs to be replaced, the electrode is removed from the welding torch and ground to remove the used portion of the electrode. Each time the electrode is ground, about 50/1,000 inch of material is removed from the electrode. The electrode is then manually repositioned in the welding torch. When the electrode is reinstalled, a distance between a tip of the electrode and the workpiece needs to be maintained constant to provide consistent results. The time needed to properly manually reinstall the electrode can shut down an assembly line, losing both time and money. Additionally, after approximately 8 to 10 regrinds, the electrode has a length of about 3.75 inch and must be replaced. This wastes a large amount of material.
A welding torch can be used to weld sheet metal workpieces together at a weld seam. In one example, the sheet metal workpieces are a roof and a body of a vehicle. Styles of vehicles are limited by the fact that there are constraints on how much metal can be stretched. A new vehicle style can be created by using several pieces of metal.